Sunday, May 29, 2022

Recent Work from the National Park Service Paleontology Program

My day job is with the Paleontology Program of the National Park Service, and I thought you might like to see some of the work we've put out over the past few months. First up is the Spring 2022 issue of the Park Paleontology newsletter. For this issue, we have articles on:

Next, a couple of articles have just come out in the latest volume of the New Mexico Museum of Natural History and Science Bulletin series, both focused on Quaternary cave paleontology of specified parks in the southwest. Hodnett et al. (2022) describes previously overlooked bones from Grand Canyon National Park as specimens of the "American cheetah" Miracinonyx trumani. Meanwhile, drawing on the Carlsbad Caverns National Park paleontological inventory published a few years ago, Kottkamp et al. (2022) discusses the Pleistocene vertebrate record of the park's various caves.

Finally, public versions of our four latest park-specific paleontological inventory reports are also available to view and download. For just four parks, they feature a wide range of types of fossils, geology, and geography. They are:


Hodnett, J. P., R. White, M. Carpenter, J. Mead, and V. L. Santucci. 2022. Miracinonyx trumani (Carnivora; Felidae) from the Rancholabrean of the Grand Canyon, Arizona and its implications on the ecology of the “American cheetah.” New Mexico Museum of Natural History Bulletin 88:157–186.

Kottkamp, S., V. L. Santucci, J. S. Tweet, R. D. Horrocks, and G. S. Morgan. 2022. Pleistocene vertebrates from Carlsbad Caverns National Park, New Mexico. New Mexico Museum of Natural History and Science Bulletin 88:267–290.

Sunday, May 15, 2022


One of the characteristic aspects of the Mifflin Member of the Platteville Formation is its habit of planar jointing. The faces of outcrops often look like someone took a rock saw to them. Nor are they necessarily single flat planes; sometimes joints intersect to form sharp angles. The heavy thunderstorms the previous week inspired a large chunk of Mifflin outcrop to collapse along intersecting joints.

Tumbled down

The joint planes did not form overnight, which can be seen by the amount of roots and soil in the new outcrop faces. There were some pretty big roots in there as well, but whatever tree(s) had once produced them is long gone.

A view into the wedge more or less along one of the two joints.

This particular rockfall was about as polite as possible, occurring not at the top of a stereotypical 30-foot bluff but from a much lower bluff, adjacent to a bike path. The orientation of the wedged stack shows that it toppled out of its former position. The top of the stack is therefore farthest from the bluff. Perhaps it failed at the base first, due to poor support from the Pecatonica, then flopped over.

History going from left to right